Once the gates close at Fright Fest's end, most people don't think about Gurnee's Six Flags Great America over the winter, said Brandon Bruce, public relations specialist.

Forgotten by most visitors during the winter, the park is blanketed in white. Icicles hang from the steel coasters. The reflection pond freezes, and the iconic merry-go-round is bagged and eventually topped with snow like a gigantic birthday cake.

Service corridors and the park's midway are plowed, but not every nook and cranny. Smaller rides frost over and the roller coaster cars are taken into a warehouse to be refreshed for next summer.

Although Six Flags' employee base goes from its summer high of more than 4,000 to a winter low of 150 people, there's still lots of work to do behind the scenes, especially for maintenance staff.

"The coaster cars are on a maintenance schedule just like your car," Bruce said.

Mark Walaszek, mechanical electrical manager, said the snow and weather are the most challenging features of the off-season.

"We try to have everything inside before Thanksgiving," Walaszek said. "What's good is we have a much more regular schedule than when the park's open."

Gesturing around a warehouse packed with Raging Bull, Demon and other coaster cars and parts, Bruce said, "In the summer, everything you see here is out in the park."

During the summer, the warehouses are full of games and merchandise. In another part of the building, the maintenance team stripped down cars for cleaning and repairs.

Katy Enrique, communications manager, said, "The rides are meant to be outside structures. The motors are taken apart [before Thanksgiving] and some rides are stripped to the bones. But the tracks aren't pre-treated with anything before it snows."

Just outside the warehouse and over the train tracks are the wooden bones of the new giant, Goliath. A special crew with experience working in winter weather was brought in to build the roller coaster, Bruce said.

The ride, slated to open around Memorial Day this year, is planned to break three world records as the fastest wooden roller coater in the world and to feature the world's tallest and steepest drop, according to park president Hank Salemi.

At this point in the build, the ride is about 15 percent done, Enrique said. The crew is installing wood stacks, which will act as the base for the track, into anchors which were placed before the ground froze. Each stack is built laying down and installed with a crane, Bruce said.

Hoses run through the ground attached to a machine that melts the snow around the work site.

The workers don't have to battle any animals who make the park their winter home, Enrique said.

"We don't get any deer," Enrique said. "There are squirrels, raccoons, sometimes families of cats – but as soon as the park opens and people are around, they're gone."

Enrique said the best thing about Six Flags in the winter is to see it covered in snow.

"It's cool to see the park totally disrupted before they plow it," she said.